This invention relates to apparati for and methods of analyzing fluid samples and has particular application in the analysis of parameters of biological fluids, such as blood and serum.
Systems for analyzing the ion level of a fluid sample by use of ion selective electrodes are known in the art. Such systems typically include an analyzer instrument which contains electrical circuitry for analyzing the ion levels of the fluid sample. The electrical circuitry is adapted to receive information from measuring units which include the ion selective electrodes. Conventional electronics, pumping and flow meters and the like are interconnected with such measuring units.
Measuring units have been used in various electrochemical measuring apparatus. U.S. Pat. No. 4,160,714 describes a single unit measuring chamber used for pH values, gas values and other types are known for use in measuring various analytes including metal ions in body fluids such as blood.
It is known to use reference electrodes and measure electromotive force between a reference electrode and an electrode mounted beneath a membrane over which a fluid is passed to determine the ionic content of the fluid. Ions such as potassium, sodium and others are customarily tested in medical laboratories by such equipment. For example, U.S. Pat. Nos. 4,627,893 and 5,019,238 disclose a testing module having units which can be arranged seriatim to provide narrow through passageways linked to each other for quantitative determination of analytes passing through the units as by electrical testing with electrodes.
A module multi-channel automated medical analyzer device characterized by use of an ion selective electrode is disclosed in U.S. Pat. No. 4,946,651. Other systems for analyzing ion levels in fluids are disclosed, for example, in U.S. Pat. No. 4,293,307; U.S. Pat. No. 4,221,457; and U.S. Pat. No. 4,946,651.